The salinity distribution within coastal waterways reflects the relative influx of fresh water supplied by rivers, and marine water supplied by exchange with the ocean. Large incursions of freshwater can severely depress normal salinity levels in estuaries, leading to habitat loss, a decrease in biodiversity, fish kills and a change in animal and plant physiology.
Indicators of excess freshwater sources:
Indicators of direct pressure:
- Total point source freshwater load entering the estuary.
Physical-chemical condition indicators:
Biological condition indicators:
|Possible causes||Possible symptoms|
|The actions/events/situations that might induce this stress:||The actions/events/situations that might arise from a change to the stressor:|
Fact sheets on background science and economics
Other information on excess freshwater
USGS Hydrologic and Geochemical Models are widely used to predict responses of hydrologic systems to changing stresses, such as increases in precipitation or ground-water pumping rates, as well as to predict the fate and movement of solutes and contaminants in water.